We will aim to address this by using well validated tests of reading and behaviour, and comparing results from these with children's fatty acid status as assessed from a pinprick blood sample. In Stage 1 we will primarily aim to establish the degree of association between fatty acid status and reading and behaviour. Secondarily, we will look at whether the children who have a higher DHA status have better sleep, and whether in turn they have better reading and/or behaviour, as previous work has suggested this.